Importance of specific coating layers?

[zouwi]

I want some colourful flare balls to my photos and I have no equipment that would make them. Instead I do have some objectives that I never use and will to experiment.

I'm planning on removing coatings from my FD 35-70mm f/4.5-4.5 zoom and stopped to think that does it matter what surfaces I clean and what I leave with coatings? Does it make a difference if I remove coatings from all sides facing film or all front surfaces? The kind of flare I want is lots of magenta/green/blue balls in a line so I think that there has to be at least some surfaces left with coatings to give the colour to those reflections. Has anyone any ideas on what surfaces the reflections usually happen and what kind of difference it makes if some specific coating is removed?

If no one comes with any ideas, I think I will just get adapter to digital and start removing coatings one surface at a time and report results.

 

[Q.G.]

Facing film or subject doesn't matter at all. Every glass-air (or air-glass) or glass-glass boundary contributes to flare.

I think the difference in colour of coloured flare is indeed caused by the coating layers. So i would not remove any to achieve that effect.
Different colours are caused by the anti-reflection coating for the complementary colour(s) failing, and that due to angle of incidence (i.e. the path length of the rays of light relative to the wave length).

How would you remove one layer without touching the next?

And do you know how many layers there are on your lens, what each does and and in what order they are? What will you do if it would turn out you would need to remove one that's inbetween two you don't want to remove?

In short: i don't think it's a good idea.

 

[railwayman3]

I'd agree that removing coatings is a rather drastic and very uncertain way of obtaining the results that you need.

If you can adapt your lens to your digital camera, you can experiment freely in any number of non-destructive ways to get the effects, using lighting, filters, vaseline or cellophane on a filter glass, etc., then apply that experience to transfer the same effect to your analogue camera.

 

[lxdude]

I can suggest you get an original Tamron Adaptall lens, the older the better. I have a 75-150/3.5 without macro from about 1978. The multi-coating from that time has a strong tendency to show multi-color flare, especially magenta. Shooting a backlit subject I have been able to deliberately get flare which renders the entire image magenta.

 

[Marco B]

Just get a couple of these crappy cheap UV filters sold everywhere and put these in front of your lens instead of ruining lenses themselves. The anti-reflection coating is usually bad on these (probably single coated), and should give you flares. I got rid of my flare problems by relying on the lenses superior coating instead

Actually, the first time I really had a serious look at the anti-reflective properties of some cheap Hoya Skylight filter I had, and compared it with the superior coating on my Sigma EX lenses by tilting them in the sun light, I was quite shocked to see the difference...

 

[Mustafa Umut Sarac]

Buy a silk curtain camera and open small holes on to it. Result will be excellent.